Bluetooth low energy (BLE) passive vehicle access control system for defending the system against relay attacks and method thereof

ABSTRACT

A Bluetooth Low-Energy (BLE) passive vehicle access control system integrated into a vehicle and an external device to defend the system against relay attacks is provided. The system includes at least one of a motion detector, a microprocessor, or a barometric pressure sensor. The motion detector is configured to detect and distinguish various types of motion and vibration. The motion detector is further configured to distinguish between a true motion event and a false motion event. The microprocessor comprises a set of computer executable instructions including a TX power profiling is capable of modulating the transmitted (TX) power level to create at a receiving end of a communication having link in the vehicle a RX power level (RSS) profile that serves as an authentication. The barometric pressure sensor is configured to measure barometric pressure which ultimately translates the measured barometric pressure into altitude value and distinguish the altitude value of the vehicle and of the external device is either matched or different.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to a U.S. provisional patentapplication Ser. No. 62/440,667, filed Dec. 30, 2016, the contents ofwhich are incorporated herein by reference as if fully enclosed herein.

FIELD

This disclosure relates generally to anti-relay attack access controlsystems and, more particularly, to a BLE passive vehicle access controlsystem for defending the system against relay attacks and methodthereof.

BACKGROUND

Unless otherwise indicated herein, the materials described in thissection are not prior art to the claims in this application and are notadmitted to the prior art by inclusion in this section.

Standard Passive Entry Systems (PES) key fobs typically operate on tworadio frequencies (RF). For example, low frequency (LF) communication isused for proximity detection and localization required for the ComfortEntry Go (CEG) functionality. Another frequency, such as ultra-highfrequency (UHF), is used to extend the communication range for RemoteKeyless Entry (RKE) functionality. Passive Entry Systems (PES) havestrict proximity/localization requirements. For example, with a PESsystem providing RKE and CEG, a vehicle unlocks the doors only when adriver or a person authorized to access is within a perimeter at ˜2 mfrom the vehicle. The PES/CEG system further allows the user or thedriver to start the engine only when the key fob is inside the vehicle.These localization requirements are hard to satisfy for any wirelesstechnology. Therefore, the current systems require LF, e.g. 125 kHz,antennas both inside and outside the vehicle along with optimal powercontrol to satisfy the proximity/localization requirements. On the otherhand, communication link from the key fob to the vehicle for RKE (i.e.,when the user explicitly presses the lock/unlock button on the key fob)is based on UHF to satisfy both the range requirement (˜50 m) and theantenna size requirement (i.e., the antenna needs to fit in a small keyfob).

These systems are vulnerable to relay attacks. In a relay attack, anattacker uses a relay apparatus such as an analog amplifier to amplifythe received signals from either the PES on the vehicle or the key foband retransmit the received signals back to either the system or the keyfob. This attack makes the key fob believes the driver is in proximityof the vehicle, so that the key fob sends an access control command inUHF to the vehicle, which in turn unlocks the vehicle. In more advancedattacks, one attacker may also employ an advanced relay apparatuscapable of measuring the power of the received signals and replicatingthe signals by adjusting the transmit power accordingly.

Electronic and wearable devices with integrated keyless passive entrysystems are becoming widely used due to several advantages. For example,the user does not require to rely on key fobs for the access of thevehicle and further the user does not require to actively interact withthe device nor the key fob with integrated PES in order to access thevehicle. However, these devices with integrated PES are also vulnerableto relay attacks.

Therefore, there is a long felt need to provide an improved passivevehicle access control system to defend the system against relayattacks.

SUMMARY

A summary of certain embodiments disclosed herein is set forth below. Itshould be understood that these aspects are presented merely to providethe reader with a brief summary of these certain embodiments and thatthese aspects are not intended to limit the scope of this disclosure.Indeed, this disclosure may encompass a variety of aspects that may notbe set forth below.

Embodiments of the disclosure related to a BLE passive vehicle accesscontrol system comprise a vehicle, an external device communicativelycoupled to the vehicle, and a processor communicatively coupled thevehicle to the external device wherein the external device is configuredto modulate a transmitted (TX) power level of successive transmissionsand generate a corresponding RX power level (RSS) profile identical tothe modulated TX power level of successive transmissions. The processoris configured to compare the RSS profile with a pre-determined securepatterns stored in a non-transitory computer-readable storage media. Theprocessor is further configured to disable a communication between theexternal device and the vehicle if the RSS profile is constant. Thesystem further comprises a sensor for detecting a perimeter, and theprocessor coupled to the sensor receives the detected perimeter anddisables a communication between the external device and the vehicle.The sensor is at least one of a motion detector or a barometric pressuresensor. The motion detector detects the perimeter comprising anacceleration data, the processor further compares the acceleration datawith a set of pre-determined criteria stored in non-transitorycomputer-readable storage media and distinguishes the acceleration datais either a true event or a false event. The processor disables thecommunication between the external device and the vehicle when theacceleration data does not match with the pre-determined criteria, isdefined as the false event. The barometric pressure sensor measuresbarometer pressure of at least one of the external device and thevehicle, the processor disables the communication between the externaldevice and the vehicle if the barometer pressure of the external devicedoes not match with the barometer pressure of the vehicle.

According to another exemplary embodiment of the disclosure, anon-transitory computer-readable storage medium having stored thereforeon a computer program for defending a system against relay attacks, thecomputer program comprises a set of instructions for causing a processorto perform measure a RX power level (RSS) profile, compare the measuredRSS profile with a pre-determined secure patterns, and disable acommunication between the receiving device and a transmitting device ifthe measured RSS profile is constant. The non-transitorycomputer-readable storage medium further comprises modulating atransmitted (TX) power level of successive transmissions and creating RXpower level (RSS) profile identical to the modulated TX power level. Thenon-transitory computer-readable storage medium further comprisesdetecting a perimeter generated by at least one of the receiving deviceand the transmitting device wherein the perimeter is at least one of anacceleration data and a barometric pressure value. The non-transitorycomputer-readable storage medium further comprises comparing theacceleration data with a set of pre-determined criteria anddistinguishing the acceleration data is either a true event or a falseevent. The non-transitory computer-readable storage medium furtherdisables the communication between the receiving device and transmittingdevice if the acceleration data does not match with the pre-determinedcriteria, defining the false event. The non-transitory computer-readablestorage medium further disables the communication between the receivingdevice and the transmitting device if the barometer pressure value ofthe receiving device does not match with the barometer pressure value ofthe receiving device.

According to yet another exemplary embodiment of the disclosure, anaccess control system for a vehicle comprises a sensor for detectingdata including at least one of a motion value, a vibration value, and abarometric pressure value of an external device and a processor incommunication with the sensor is configured to disable a connectionbetween the external device and the vehicle. The processor receivesdetected data from the sensor and compares the detected data with apre-determined criteria wherein the pre-determined criteria is at leastone of minimum motion value, maximum motion value, and no motion value.The processor is further configured to measure a RX power level (RSS)profile, compare the measured RSS profile with a pre-determined securepatterns, and disable the connection between the external device and thevehicle if the measured RSS profile is constant. The processor receivesthe detected data from the sensor and is further configured to translatethe detected data into an altitude value, compare the altitude value ofthe external device with an altitude value of the vehicle, and disablethe connection between the external device and the vehicle if thealtitude value of the external device and the altitude value of thevehicle is not matched.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of this disclosurewill become better understood when the following detailed description ofcertain exemplary embodiments is read with reference to the accompanyingdrawings in which like characters represent like arts throughout thedrawings, wherein:

FIG. 1 is a block diagram of a system according to a describedembodiment of the disclosure;

FIG. 2A is a graph showing RSS profile data in accordance with thedisclosure;

FIG. 2B is another graph showing RSS profile data in accordance with thedisclosure; and

FIG. 3 is a block diagram of a system according to another describedembodiment of the disclosure.

DETAILED DESCRIPTION

The following description is presented to enable any person skilled inthe art to make and use the described embodiments, and is provided inthe context of a particular application and its requirements. Variousmodifications to the described embodiments will be readily apparent tothose skilled in the art, and the general principles defined herein maybe applied to other embodiments and applications without departing fromthe spirit and scope of the described embodiments. Thus, the describedembodiments are not limited to the embodiments shown, but are to beaccorded the widest scope consistent with the principles and featuresdisclosed herein.

FIG. 1 illustrates a system 10 in accordance with a disclosure. Thesystem 10 is a passive vehicle access control system comprises a vehicle12 and an external device 14 communicatively coupled to the vehicle 12via a communication link. As illustrated, the communication link is aBluetooth (BT) communication protocol and standard including a BluetoothLow Energy (BLE) communication protocol. The external device 14 may beany BLE-enabled device such as a key/card device or any other clientdevice. The external device 14 also includes passive vehicle accesscontrol functionality generally known to the industry. The key/carddevice may be a key fob, key card, a client device, an access key, anaccess card, a smart card, a smart key, or any suitable BLE-enableddevice. The client device may be a smart phone, a personal digitalassistant (PDA), a tablet, a laptop, a portable personal computer, aphablet, a wearable device, a thin device, a thick device, anentertainment device, an infotainment device, or any suitableportable/wearable device including Bluetooth low energy protocol or anysuitable BT communication protocol. As illustrated, the key/card deviceis a smart key 18 and the client device is a phablet 16, both with BLEpassive vehicle access control. A plurality of wireless transceivers 20,22, 24, 26 comprises integrated antenna are installed at variouslocations in and around the vehicle 12. In one embodiment, the antennais a directional antenna. Depending on the application, other suitableantenna either integrated into or coupled to the transceivers. Forexample, wireless transceiver 20 and 24 are installed near the handle ofthe front doors. Wireless transceiver 22 is installed near the rear endof the vehicle, whereas wireless transceiver 26 is installed at thefront end of the vehicle. For instance, the wireless transceiver 26 islocated at a location near to a dashboard. As can be seen, except thewireless transceiver 26 that faces toward the inside of the vehicle, therest of the wireless transceivers 20, 22, 24 are facing outwardly. Anynumber of transceivers 20, 22, 24, 26 periodically transmit signals suchas advertisement beacons to announce the presence of the vehicle 12 toat least one of the smart key 18 or the phablet 16 carried by a driveror an authorized person of the vehicle 12. When one of the smart key 18or the phablet 16 receives these advertisement beacons, one of the smartkey 18 or the phablet 16 starts or initiates the connection andauthentication process with the vehicle 12 via for example thetransceivers 20, 22, 24, 26. During this process, the vehicle 12 and oneof the smart key 18 or the phablet 16 continuously exchange datapackets. At the completion of this process, one of the smart key 18 orthe phablet 16 periodically transmits beacons while either any number ofthe transceivers 20, 22, 24, 26 or a BLE-enabled passive vehicle accesscontrol device coupled to the transceivers 20, 22, 24, 26 measuresReceived Signal Strength (RSS) of these beacons in order to estimate theposition of one of the smart key 18 or the phablet 16. The BLE-enabledpassive vehicle access control device is also located on the vehicle 12.In some embodiments, more than one BLE-enabled passive vehicle accesscontrol device may be installed in the vehicle 12 and then coupled toany in-vehicle devices via any number of communication links. In someembodiments, the BLE enabled passive vehicle access control device isremotely located outside the vehicle 12 and is communicatively coupledto the vehicle 12 via any suitable communication interface. In anotherembodiments, the BLE enabled passive vehicle access control device islocated in a network. The network can be, for example, a local-areanetwork (LAN), a metropolitan area network (MAN), a wide area network(WAN), a primary network comprising multiple sub-networks locatedbetween the vehicle 12 and the external devices 14, a cloud network, andso forth. The yet embodiment, the BLE enabled passive vehicle accesscontrol device is located on a serer. The cloud network can be a publiccloud network, a private cloud network, for example.

To increase the level of security in controlling the access to thevehicle and to defend the system 10 against relay attacks performedduring the communication established between the vehicle 12 and theexternal device 14, a motion detector 28 disposed in the external device14 is provided. The motion detector 28, in one embodiment, includes anaccelerometer, and is configured to detect and distinguish among varioustypes of motion and vibration. In some embodiments, the motion detector28 includes a motion sensor, a gyroscope, a magnetometer, a vibrationsensor, or any other suitable sensors. A desired program code in theform of a set of computer-executable instructions or data structures maybe stored in the motion detector 28 and the instructions allow themotion detector 28 to detect and distinguish various types of motion andvibration. A processor coupled to the accelerometer 28 receives themeasured information including acceleration data, compares theacceleration data with a set of pre-determined criteria as described indetail below, and distinguishes the acceleration data associated with amotion or vibration of the external device 14. Further, the processoranalyzes the acceleration data to determine if a sequence of motion andvibration matches with a set of pre-determined criteria, i.e. anexpected sequence of motion and vibration. A set of pre-determinedcriteria includes a significant or maximum motion, e.g. walking towardsor away from the vehicle, a minimum motion, e.g. single step detection,a no motion, e.g. no change in location, a vibration mode, or so forth.If the sequence of motion and vibration does not match with the set ofpre-determined criteria, a bi-directional communication between thevehicle 12 and the external device 14 is disabled, which in turndisrupts any relay attacks.

The motion detector 28 of the external device 14 or the processorlocated in the vehicle 12 may be configured to distinguish between atrue motion event and a false motion event. For example, the processorlocated in the vehicle 12 receives the measured information includingacceleration data from the motion detector 28, compares the accelerationdata with a set of pre-determined criteria, and distinguishes theacceleration data between a true motion event and false motion event. Ifthe event is determined to be a false motion event, i.e. the externaldevice 14 is not moving, then the bi-directional communication betweenthe vehicle 12 and the external device 14 is disabled to defend thevehicle 12 and the external device 14 against any relay attacks. Theprocessor and the accelerometer may be integrated into the motiondetector 28, in one example. In another example, the processor islocated somewhere inside the external device 14 and is an independentcomponent from the motion detector 28. In yet another example, theprocessor is located in the vehicle 12 and the motion detector 28 iscommunicatively coupled to the processor.

To provide another level of security in controlling the access to thevehicle and to defend the system 10 against relay attacks during thecommunication established between the vehicle 12 and the external device14, a microprocessor 30 having a set of computer executable instructionsincluding a TX power profiling is provided. During the connection andauthentication phase, the external device 14 and the vehicle 12 transmitto each other several packets. For example, the transmitting device,such as the external device 14, modulates the transmit (TX) power levelof successive transmissions according to a specific and secret patternso to create at a receiving end of the communication link, such as thevehicle 12, an identical RX power (RSS) level profile that serves as anauthentication before a connection between the external device 14 andthe vehicle 12 is established. The receiving end of the communicationlink in the vehicle 12 measures the RX power (RSS) level of successiveincoming signals, compares the RX power level of successive incomingsignals with the pre-defined secure pattern stored in a machine readablemedium. The machine readable medium may be located in either the vehicle12, the external device 14, the network, or the server. If the RSS ofthe incoming signals is constant, a communication between the vehicle 12and the external device 14 is disabled, which in turn disrupts any relayattacks. FIG. 2A shows the graph 40 of the constant RSS profilegenerated by an attacker. Now referring to FIG. 2B, a secret TX powerprofile generates a specific and secret RSS profile pattern illustratedas a graph 48. As can be seen, both vehicle 12 and external device 14are able to detect the presence of a relay attack by measuring the powerof the received signals and then comparing the resulting RSS profilewith the pre-defined and secure TX power profile. In one embodiment, thesame packet (message) is transmitted multiple times during theconnection and authentication phase by varying transmit power level. Inanother embodiment, each packet (message) is transmitted during theconnection and authentication phase by varying the transmit power level.In yet another embodiment, the transmit power level used to transmit thepacket (message) may be added to the payload of the encryptedtransmitted packet. The receiving end of the communication link in thevehicle 12 measures the RSS of the received packet and adds this valueto the payload of the encrypted response packet. In turn, thetransmitting device 14 further uses this information to adjust its owntransmit power level to the same level.

FIG. 3 illustrates another system 60 in accordance with a disclosure.The system 60 is identical to the system 10 illustrated in FIG. 1,except that the system 60 includes a barometric pressure sensor 64configured to measure barometric pressure, which ultimately translatesthe measured barometric pressure into altitude value. If the altitudevalue of the vehicle 12 does not match with the altitude value of theexternal device 14, a bi-directional communication between the vehicle12 and the external device 14 is disabled, which in turn disrupts anyrelay attacks. This altitude or barometric pressure reading processprovides a level of security in controlling the access to the vehicle 12and to defend the system 60 against relay attacks during thecommunication established between the vehicle 12 and the external device14. In one embodiment, the barometric pressure sensor 64 is integratedinto the motion detector 28. In another embodiment, the barometricpressure sensor 64 may be a separate component is communicativelycoupled to the motion detector 28. A suitable program code in the formof a set of computer-executable instructions or data structures may bestored in the barometric pressure sensor 64 and the instructions causethe barometric pressure sensor 64 to measure barometric pressure leveland compare the resulting altitude of the vehicle 12 and the externaldevice 14. In some embodiments, a processor, previously described inFIG. 1, not only is capable of comparing the acceleration data collectedby the accelerometer 28 with a set of pre-determined criteria anddistinguishing the acceleration data associated with a motion orvibration of the external device 14, but the processor is also capableof comparing the altitude of the vehicle 12 and the external device 14.

The embodiments described above have been shown by way of example, andit should be understood that these embodiments may be susceptible tovarious modifications and alternative forms. It should be furtherunderstood that the claims are not intended to be limited to theparticular forms disclosed, but rather to cover all modifications,equivalents, and alternatives falling with the sprit and scope of thisdisclosure.

Embodiments within the scope of the disclosure may also includenon-transitory computer-readable storage media or machine-readablemedium for carrying or having computer-executable instructions or datastructures stored thereon. Such non-transitory computer-readable storagemedia or machine-readable medium may be any available media that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, such non-transitory computer-readablestorage media or machine-readable medium can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium which can be used to carryor store desired program code means in the form of computer-executableinstructions or data structures. Combinations of the above should alsobe included within the scope of the non-transitory computer-readablestorage media or machine-readable medium.

Embodiments may also be practiced in distributed computing environmentswhere tasks are performed by local and remote processing devices thatare linked (either by hardwired links, wireless links, or by acombination thereof) through a communications network.

Computer-executable instructions include, for example, instructions anddata which cause a general purpose computer, special purpose computer,or special purpose processing device to perform a certain function orgroup of functions. Computer-executable instructions also includeprogram modules that are executed by computers in stand-alone or networkenvironments. Generally, program modules include routines, programs,objects, components, and data structures, etc. that perform particulartasks or implement particular abstract data types. Computer-executableinstructions, associated data structures, and program modules representexamples of the program code means for executing steps of the methodsdisclosed herein. The particular sequence of such executableinstructions or associated data structures represents examples ofcorresponding acts for implementing the functions described in suchsteps.

While the patent has been described with reference to variousembodiments, it will be understood that these embodiments areillustrative and that the scope of the disclosure is not limited tothem. Many variations, modifications, additions, and improvements arepossible. More generally, embodiments in accordance with the patent havebeen described in the context of particular embodiments. Functionalitiesmay be separated or combined in blocks differently in variousembodiments of the disclosure or described with different terminology.These and other variations, modifications, additions, and improvementsmay fall within the scope of the disclosure as defined in the claimsthat follow.

What is claimed is:
 1. A Bluetooth Low Energy (BLE) passive vehicleaccess control system comprising: a wireless transceiver located in avehicle; an external device configured to communicate with the wirelesstransceiver located in the vehicle; and a processor located in theexternal device; a barometric pressure sensor located in the externaldevice, the barometric pressure sensor being configured to measurebarometer pressure at the external device and send the measuredbarometric pressure to the wireless transceiver; wherein the processorlocated in the external device is configured to: modulate a transmitted(TX) power level of successive transmissions from the external device tothe wireless transceiver in the vehicle using a predetermined pattern ofpower levels stored in a non-transitory computer-readable storage mediain the external device and not received from the wireless transceiver soat least one transmission in the successive transmissions from theexternal device has a transmitted power level that is less than apreceding transmission in the successive transmissions from the externaldevice; and wherein the wireless transceiver located in the vehicle isconfigured to: generate a RX power level (RSS) profile corresponding toa power level of each successive transmission received from the externaldevice, compare the generated RSS profile with a predetermined patternof power levels stored in a non-transitory computer-readable storagemedia in the vehicle and not received from the external device; disablecommunication between the external device and the wireless transceiverwhen the RSS profile does not match the predetermined pattern of powerlevels; receive the measured barometric pressure from the barometricpressure sensor and translate the measured barometric pressure to analtitude of the external device; compare the translated altitude of theexternal device to an altitude of the wireless receiver; and disablecommunication between the external device and the wireless transceiverlocated in the vehicle when the translated altitude of the externaldevice does not match the altitude of the wireless receiver.
 2. The BLEpassive vehicle access control system of claim 1 further comprising: amotion detector located in the external device, the motion detectorbeing configured to generate acceleration data corresponding to movementof the external device and transmit the generated acceleration data tothe wireless transceiver; and the wireless transceiver is furtherconfigured to compare the acceleration data received from the motiondetector in the external device with predetermined criteria stored inthe non-transitory computer-readable storage media located in thevehicle and to determine whether the acceleration data corresponds to atrue event or a false event.
 3. The BLE passive vehicle access controlsystem of claim 2 wherein the wireless transceiver disablescommunication between the external device and the wireless transceiverlocated in the vehicle when the wireless transceiver determines theacceleration data does not match with any of the predetermined criteriaor determines the acceleration data corresponds to the false event. 4.An access control system for a vehicle comprising: a sensor forgenerating and transmitting data corresponding to a barometric pressureat an external device; and a processor in a vehicle that is configuredto: measure a RX power level (RSS) profile of successive transmissionsreceived from the external device; compare the measured RSS profile ofthe successive transmissions with a predetermined pattern of RX powerlevels, at least one of the power levels in the predetermined pattern ofpower levels being less than at least one preceding power level in thepredetermined pattern of power level; disable communication between theexternal device and the processor in the vehicle when the measured RSSprofile of the successive transmissions does not match the predeterminedpattern of RX power levels, receive the generated data corresponding tothe barometric pressure transmitted from the sensor and translate thegenerated data corresponding to the barometric pressure transmitted fromthe sensor into an altitude value at the sensor; compare the altitudevalue at the sensor with an altitude value at the vehicle; and disablecommunication between the external device and the processor in thevehicle when the altitude value at the external device and the altitudevalue at the vehicle do not match.